




m a : 


W&mm 


9i 






vVr/5 


'JV 


%mmmm 


mmm 


tt&yy?. 

B»wew» 




























COPYRIGHT DEPOSIT. 









t 


































** 














'Bhe GARDEN of the WORLD 


UNIFORM WITH THIS VOLUME 


HOW THE WORLD BEGAN 

The Story of the Beginning of Life on Earth 

HOW THE WORLD GREW UP 

The Story of Man 

HOW THE WORLD IS RULED 

The Story of Government 

THE WORLD OF ANIMALS 

The Story of Animals 

HOW THE WORLD IS CHANGING 

The Story of Geology 

THE WORLD’S MOODS 

The Story of the Weather 

THIS PHYSICAL WORLD 

The Story of Physics 

WHAT MAKES UP THE WORLD 

The Story of Chemistry 

OTHER WORLDS THAN THIS 

The Story of Astronomy 


Thomas S. Rockwell Company 
Publishers 
CHICAGO 










II 


Publishers Note 


This book presents in popular form the 
present state of science. It has been reviewed 
by a specialist in this field of knowledge. An 
excerpt from his review follows: 


"/ believe that'The Garden of the 
World* will go far toward satisfy¬ 
ing the child's natural curiosity 
about plants. The contents are well 
chosen and attractively presented ” 


Signed: Merle C. Coulter, 
Associate Professor of Plant Genetics 
The Department of Botany 
The University of Chicago 







“Yon pretty daughters of the Earth and Sun' u 

THE SHEPHERD TO THE FLOWERS 

Sir Walter Raleigh 
















































THE GARDEN 
OF THE WORLD 


By 

Janet McGill 

% » 

Drawings by 
Electra Papadopoulos 


THOMAS S. ROCKWELL COMPANY 
Chicago 
1930 


* 


1.0 



Copyright, 1930, by 

THOMAS S. ROCKWELL COMPANY 

CHICAGO 


Printed in United States of America 


a $$ 

©CIA 


28671 


CONTENTS 


I Plants without Seeds ii 

What is the green scum on water? What are the 
smallest plants? What causes bread to mold? 
What is moss? What are ferns? 

II Friends and Enemies 26 

Why are sunflowers yellow? How do plants club 
together? Why do flowers open and close? Why 
do so many red flowers have long narrow tubes? 
How do plants protect themselves? Why do 
burrs stick? 

III Sunlight Factories 45 

How do plants climb? How do plants get their 
food? How can we tell the age of trees? How 
do roots worf(? 

IV Food for Plants 58 

Why is it hard to grow flowers in the shade of a 
tree? What plants are pirates? What plants trap 
their food? Why is clover good for the grass? 

Why do dandelions ^/ 7 / the grass? 

V Storage Rooms 69 

What are vegetables? Why do leaves drop in the 
autumn? What is a seed? What are bulbs? 

Why are there laws against picking wild flowers? 

VI Man-Made Plants 84 

Will oranges grow on lemon trees? How do 
farmers get better apples? How did Burbank 
produce the Shasta Daisy? 


95 


VII A World of Gardens 

How do water lilies grow? Why is a cactus full 
of water? Why do dates grow in the desert? 
What plants grow in the cold deserts? What is 
the most important family in the plant hjngdom? 
What are the most troublesome plants? Why do 
forests need protection? 


LIST OF ILLUSTRATIONS 


HOW CELLS ARE DIVIDED 12 

THE SHAPES OF BACTERIA 17 

SOME FUNGI GROW ON TREES 23 

FERNS DO NOT HAVE SEEDS 25 

SEEDS MUST BE POLLINATED 27 

THE SUNFLOWER INVITES THE BEES 29 

CLOVER IS MADE OF MANY BLOSSOMS 31 

SOME FLOWERS ARE MANY IN ONE 33 

THE HUMMING BIRD’S BILL REACHES THE NECTAR 38 
ROSES PROTECT THEMSELVES FROM CRAWLERS 41 
BURRS HAVE ONE PURPOSE 42 

BURRS TRAVEL A LONG WAY 43 

CLIMBERS HAVE DIFFERENT METHODS 46 

MORNING GLORIES MUST HAVE A SUPPORT 47 

LEAVES ARE FACTORIES WORKING IN THE SUN 50 
THE AGE OF TREES CAN BE TOLD 51 

THE RINGS OF A TREE 53 

DIFFERENT ROOT FORMS 55 

A TREE’S ROOTS REACH FAR 57 

THE DODDER HAS NO ROOTS 61 

PLANTS THAT TRAP FOOD 63 

THE DANDELION HAS MANY WEAPONS 67 

POTATOES ARE TUBERS 69 

A COMMON BULB, LEAF, AND FRUIT 70 

MANY SEEDS ARE GOOD TO EAT 71 

TREES DROP LEAVES TO SAVE WATER 73 

THE STORAGE ROOM OF SEEDS 75 

BULBS ARE STUFFED WITH PLANT FOOD 78 

TULIPS GROW BEST FROM BULBS 79 

WILD FLOWERS SHOULD NOT BE PICKED 83 

THE BUD BEARS ITS OWN KIND OF FRUIT 85 

GRAFTING CAN IMPROVE THE FRUIT 89 

BURBANK CREATED THE SHASTA DAISY 91 

WATER PLANTS ARE OF MANY KINDS 97 

CACTI ARE FOUND IN DRY PLACES 99 

SOME OASES HAVE THOUSANDS OF DATE PALMS 101 
ALPINE PLANTS MUST GROW QUICKLY 102 

CORN IS A GRASS 104 

BAMBOO IS THE TALLEST GRASS 105 




























Chapter I 


PLANTS WITHOUT SEEDS 

r I ^HE green scum that floats on ponds of 
stale water is made of many hundreds of 
small plants. There are usually many kinds of What is the 
these plants in one pond, but they are all very 
small. Each plant is only one cell. A cell is a 
mass of living matter enclosed in a wall which 
protects it. Every cell is so small that it can be 
seen only through a microscope. Every living 
thing is made up of cells. These tiny plants 
which grow in the ponds have just one cell, but 
in spite of their small size, they are independent 
and well able to do all of the different kinds of 
plant work. 

A plant, no matter what its size, has three 
kinds of work to do: it must grow; it must get 
food; and it must always provide for the 
growth of new plants. 


11 


12 


THE GARDEN OF THE WORLD 


These one-celled plants grow by dividing the 
cell into two or more parts. A wall will grow 
through the center of the cell, dividing the liv- 


Another cell is formed by a wall that divides the 
original cell into two parts 

ing part into two pieces. When the wall is 
finished, the cell will split in two and each part 
is then a complete cell ready to carry on the 
work of the plant. 

These one-celled plants are green. This is 
important because it means that each cell 
contains a substance called chlorophyll (pro¬ 
nounced klo'ro-fil). All plants which contain 
chlorophyll are able to manufacture food for 
themselves. The cell can take carbon dioxide 






PLANTS WITHOUT SEEDS 


*3 


from the air and water from the pond and with 
the help of the chlorophyll turn them into food 
that the plant can use in its growth. 

The pond scums provide for new plants in at 
least two ways. One is by dividing the cells as 
was mentioned before. Each division of the 
old cell is a new plant. It can go on starting 
new plants by this method so long as the 
weather is favorable, but when the pond freezes, 
the plants die. New plants are started the next 
spring by means of spores. A spore is a special 
cell which has dried up. It can live a long time 
without moisture or warmth. It doesn’t grow 
but just rests. When the good growing weather 
comes again, the spore is ready to start a new 
plant. In this way a spore is something like a 
seed, but it is not a seed. It is not formed in the 
same way, nor is it made of the same parts. 

The pond scums belong to a large family of 
plants known as the Algae (pronounced Arje). 
The other plants in the family are not all so 
small as these, but they are all very simple. The 
large brown seaweed is an alga. None of the 


M 


THE GARDEN OF THE WORLD 


algae are very important to us. They are not 
good for food, and they are not even dangerous 
as some of the simple plants, like bacteria, are. 
People often have an idea that pond scum is 
poisonous. It really is harmless, but the water 
in these ponds often contains poisonous bacteria 
so it is not safe for drinking. 

If the algae are not important in themselves, 
however, they are very important in the history 
of plants. Probably the very first plants in the 
world were one-celled just like the green scum 
floating on ponds. Gradually, through millions 
of years, they changed and finally became the 
complicated plants with stems, leaves and roots 
which we have now. We are sure that the very 
first plants grew in the water because simple 
plants can grow much better there. They do 
not have to provide against drying out as the 
land plants do. Every living cell must be full 
of water. This is always true whether the cell 
is growing alone or as one of many in a large 
and complicated plant. It is true of animal 
cells also. Plants which do not live in water 


PLANTS WITHOUT SEEDS 




must have thick walls or skin to keep the water 
from evaporating, and they need root systems 
to get the moisture from the ground. 

Green scum on the water is made of the living 
members of the family that were the very first 
of all plants that ever lived on the earth. 

The smallest plants are so small that no one 
knew they existed until about one hundred 
years ago. Until the time when microscopes 
were invented, people did not even suspect that 
there were such things. They are called bac¬ 
teria, and in spite of their small size, they are 
very important to the lives of human beings. A 
great many of them are useful. They help us to 
get linen fiber, to tan leather, to turn milk sour, 
to make cheese and butter, to make vinegar, and 
to get rid of dead plant and animal material. A 
few are very harmful; they spoil food which we 
wish to eat, and they cause a great many dis¬ 
eases. We often call the harmful bacteria by 
the name of germs or microbes. 

Let us see how these bacteria work. In order 
to see them at all we must use a powerful micro- 


What are the 
smallest plants? 


16 THE GARDEN OF THE WORLD 

scope. Even then they seem to be very tiny. 
None of them are large enough to be seen by 
the eye alone. They come in three different 
shapes, like balls, lead pencils, or corkscrews. 
They are only shaped like these articles, but 
are nothing like them in size. They do not 
produce seeds, but they multiply by dividing 
into two pieces. It is a very simple perform¬ 
ance. Each plant becomes thin in the middle 
and finally breaks apart. Each new piece 
continues to grow and breaks apart again. They 
do this very fast. One plant can produce one 
million new plants in twenty-four hours. 
Usually after dividing, they separate, but some 
kinds hang together in strings, or bunch to¬ 
gether in clusters. Some of the bacteria have 
little hairlike feelers and with these they can 
swim about very freely. They are not green, 
and they do not make their own food, but take 
food which is already made from the place 
where they are living. If they cannot get food 
suited to them, they die. Bacteria are found 
everywhere on the face of the earth. They are 


PLANTS WITHOUT SEEDS 


in the ground, in the water, in the air, clinging 
to our bodies, clothing, and food. They are 



Bacteria are of three shapes — li\e balls, lead 
pencils, and corkscrews 


ever present, but we seldom think of them until 
they are harmful to us. 

There are a great many more useful bacteria 


THE GARDEN OF THE WORLD 


than there are harmful ones. In fact, there 
would be no life upon the earth at all if it were 
not for the bacteria of decay. When a great 
tree dies and falls, these bacteria attack it, and 
gradually it crumbles and disappears. The 
task takes years, but is finally finished. When 
animals die, the bacteria of decay dispose of 
them also. If the plants and animals which 
had once lived on the earth did not decay, but 
were still lying about, it would be impossible for 
us to live at all. 

We want the milk that we drink to be sweet 
and fresh, but we need sour milk also. It is 
used to make butter and cheese. There is a 
certain kind of bacteria that turns milk and 
cream sour. Another group of bacteria turns 
cider into vinegar. There are thousands of 
helpful kinds. 

Some bacteria, for all their small size, have 
the dangerous power of making poisons. They 
seem to be able to change the food they have 
used into substances that are poisons for people 
and animals. That is what these disease bac- 


PLANTS WITHOUT SEEDS 


*9 

teria do when they get into our bodies. Once 
they are in, they grow and multiply, and of 
course the more of them there are, the more 
poison they make. Sometimes our bodies are 
strong enough to resist this poison and throw it 
off. At other times it is too strong and makes 
us sick. Of course the best way to prevent sick¬ 
ness is to keep the bacteria out. They come in 
chiefly through our mouths, noses, and cuts in 
the skin. They cannot stand heat. We can 
kill them by boiling food, and by washing 
articles that may carry bacteria in boiling water. 
This is called sterilizing. Diphtheria, tubercu¬ 
losis, and influenza are three common diseases 
brought by bacteria. 

The farmer is fighting bacteria all the time. 
They cause diseases of plants as well as of ani¬ 
mals and people. They get through the skins 
of fruit and vegetables that have been cut or 
bruised and cause them to spoil. They spoil 
meat. They produce bad odors, and are the 
cause of most of the smells around the barn. 
The farmer’s best weapon in fighting them is 


20 


THE GARDEN OF THE WORLD 


What causes 
bread to mold? 

cold. They cannot spoil fruit and meat which 
are kept cold. The ice box is one of our best 
protections against harmful bacteria. 

It is interesting and very easy to grow a little 
crop of bread mold to study. Moisten a piece 
of bread with water, leave it exposed to the air 
for a short time, and then put it into a covered 
tumbler. Keep it covered and in a warm 
place. In a day or two, it will be covered with 
fluffy white stuff that looks like cotton. In 
another day there will be tiny black balls 
scattered over the fluff. If you break these, a 
fine black powder comes out and floats away. 

The white cottony material forms the roots 
and stems of the bread mold plant. The roots 
go all through the piece of bread to soak up food 
and moisture. (It cannot grow unless the 
bread is moist.) The black powder is made 
up of a great many spores. Spores are not 
seeds, but they take the place of seeds for some 
plants. They are so small as to be invisible, 
and the air is full of them. When a spore 
happens to alight on a good place to grow, it 


PLANTS WITHOUT SEEDS 


21 


can produce a new plant. Spores, which you 
cannot see, floating about in the air, settled on 
your piece of bread and grew into the bread 
mold you found. The blue colored mold 
which grows on jam and cheese and other foods 
is a relative of the bread mold. 

All the molds belong to the Fungus family. 
They are larger than bacteria, but are much 
more simple in their formation than the green 
plants. They do not make their own food but 
steal it. Therefore, they are parasites, a word 
which means “eating at another’s table.” They 
are usually not poisonous, but harm us by spoil¬ 
ing the food we want to eat. They must have 
warmth and moisture in which to grow. We 
can protect our food by keeping it cool and dry. 
Molds are not so dangerous as bacteria, but they 
do quite a lot of damage. They do not attack 
living plants or animals, and they do not enter 
into our bodies to cause disease as do bacteria. 
Bacteria and molds often grow together, as 
they both like warmth and moisture. Boiling 
or cold temperatures will kill both of them. If 


22 


THE GARDEN OF THE WORLD 


What is moss? 


we cook our meat and keep our apples in the 
ice box, neither of these enemies will attack 
them for a long time. Bread should be kept cool 
and dry and away from the air where the spores 
of bread mold are always floating. 

Bread molds belong to a family of plants 
which are called fungi. Other members of the 
family which you may know are these: mush¬ 
rooms, wheat rust, puff balls, and the large fun¬ 
gus brackets which are often seen on trees. 
These different kinds of fungi do not look at all 
alike, but they are known to belong to the same 
family because they are not green and cannot 
make their own food and because they do not 
produce seeds but form new plants by dividing 
cells or by making spores. 

The plants of the moss family are very simple. 
They are not quite so simple as the algae, for 
they are able to live on land. They have roots, 
stems, and leaves. All of these parts are very 
simple, but they are a step towards the higher 
plants which are now so common. The algae 
were probably the first plants in the world. 


PLANTS WITHOUT SEEDS 


23 


The first land plants were the liverworts. 
These are like the algae except that they de¬ 
veloped roots and thicker cell walls to keep the 
water from drying out. The liverworts could 
live on land, but it had to be moist. They 
could not stand more than a short dry spell. 
The mosses seem to have come next after the 
liverworts, for although they grow in moist 
places, they are able to stand short periods of 
dry weather fairly well. 

Mosses grow close together. The clusters of 
plants soak up water and hold it like a sponge. 
That is one way in which they provide against 
drying out. All parts of the plant, however, 
must be near to the water, for there is no system 
of tubes to carry the moisture from the roots to 
the leaves. The absence of tubes shows that the 
mosses came early in the history of plants. 

Mosses sometimes send up little shoots that 
look like flowers. They are not flowers, al¬ 
though we might call them the great grand¬ 
mothers of flowers, and they do not produce 
















24 


THE GARDEN OF THE WORLD 


What are ferns? 


seeds but spores. A spore is only a special cell 
that is able to stay alive over a long resting 
period. At the end of that time, it can grow 
and develop into a new plant. A seed is a 
much more elaborate arrangement than a spore. 

Mosses are pretty to look at and soft to feel, 
but they are chiefly interesting to us when we 
study the history of plants. They are the first 
plants which managed to live successfully on 
the land. 

Ferns were once more important than they 
are now. In the time, ages ago, when coal was 
being formed, ferns were the most plentiful of 
all plants. We know this because the imprint 
of fern leaves is often seen in coal, much more 
often than the print of any other kind of leaves. 

Ferns show a big improvement over mosses 
in the attempt of plants to grow well on land. 
The new parts which they developed are tubes 
which carry water from the roots to all parts of 
the plant. Mosses cannot grow very large be¬ 
cause when they get away from the ground, 
they cannot get water, but ferns can grow tall 


PLANTS WITHOUT SEEDS 


25 


because these tubes carry water to any part of 
the plant that needs it. During the coal-form¬ 
ing ages, many ferns were as tall as trees. In¬ 
deed there are tree-ferns still, but they grow only 
in warm countries, or in green-houses. It is a 
big advantage for a plant to be able to grow tall, 
for then its leaves can get more sunlight. Sun¬ 
light is necessary for the manufacture of food. 
From this advantage comes another one: if a 
plant can manufacture a great deal of food, it 
can store some away for the winter season. 
Then it can stay alive all winter and be ready 
to grow in the spring. The mosses and earlier 
plants never have extra food nor storage places. 
The ferns are a big improvement over them. 
They can stay alive much longer. 

The ferns, like the mosses, produce new 
plants by means of spores. The next plant that 
developed in the history of plants was able to 
have true seeds. 


* 


& 



Chapter II 


Why are sun¬ 
flowers yellow? 


FRIENDS AND ENEMIES 

W E ENJOY the brilliant colors of many 
flowers, but the plant is not trying to 
attract us when it puts on its golden petals. It 
is attracting the bees and wasps who have an 
eye for color also. The sunflower is anxious 
for the bees and wasps to see it and to visit it, 
for unless they do, it may never have any seeds. 

Every plant has three objects in life: to live, 
to grow, and to produce other plants like itself 
to carry on its life when this plant has died. 
Most of our common plants accomplish this 
third object by means of seeds. You all know 
the hard, dry seeds which we plant in the 
garden, but perhaps you have not paid so much 
attention to the young seeds. The seeds are 
born in the flowers. If you pull the center of 
a sunflower early in the summer, you will see 


26 


FRIENDS AND ENEMIES 


27 


the baby seeds, which are white and milky. At 
the end of August or early in September, you 
will find that they have become hard and dry 
and much darker in color. Now a curious 
thing about seeds is that they never become full 



The seeds will never become full grown 
unless they have been pollinated 

grown so that they can be planted unless they 
have been pollinated. That is what makes the 
difference between the baby seeds and the ripe 
ones which grow into new flowers. 






28 


THE GARDEN OF THE WORLD 


Pollen is the yellow powder that comes off 
on your fingers if you rub them across a flower. 
The part of the flower that holds the baby seeds 
is called the pistil . It usually has a sticky point 
called the stigma . The pollen must be put on 
to this stigma in order for it to get to the young 
seed. It might just happen to fall there, or 
the wind might blow it, but the sunflower can¬ 
not depend on such uncertain methods. If a 
bee, however, should walk across the flower, 
the pollen would stick to his hairy body, and 
then, when he rubbed against the sticky point of 
the stigma, it would be rubbed off again. There 
are so many stigmas close together on one sun¬ 
flower that one bee would pollinate a great 
many. This, then, is the very best way for the 
sunflower to have its seeds ripen, so it tries in 
every way to make itself attractive to bees and 
wasps. But the insects do not pollinate the 
flower just to help it out. They want some¬ 
thing for themselves. What they are after is 
the pollen. They eat it and feed it to their 
young. The sunflower has a great deal more 


FRIENDS AND ENEMIES 


29 


pollen than it needs, so the insects may carry 
off all they wish without hurting the flower. 
When a bee is out hunting for pollen, he goes 
to the plant that he sees first. Yellow is a very 
noticeable color, so the sunflower puts on big 
yellow petals to make itself as gay and bright 
as possible. It is necessary for the plant’s future 
life that the bee sees it, and the bee usually does. 
The sunflower also puts its yellow flowers on the 
top of a tall straight stem to make them tower 
above all the other flowers in the garden. This 
helps the bee to find it. 

The sunflower is not the only flower that in¬ 
vites insect visitors by its gay coloring. Nearly 
all bright colored blossoms have the same 
object; the sweet peas, the clover, the daisies, the 
iris, and the phlox are a few of them. The 
sweet smelling flowers, too, give off their fra¬ 
grant odors so that the insects which do not see 
very well find them by the sense of smell. 

We do not know exactly why the sunflower 
is yellow rather than some other color nor what 
causes the difference in shades among the 













30 


THE GARDEN OF THE WORLD 


How do plants 
club together? 


flowers. The color is made by a substance 
called anthocyan (pronounced an-tho-si-an), 
but men who study flowers do not know a great 
deal about this substance. 

A fact which we must never forget for a 
moment when we are thinking about flowers is 
that the flower is only interested in attracting 
insects to itself so that its seeds may be polli¬ 
nated. Large flowers like the water lily are 
easily seen, and they can get along by them¬ 
selves. Small flowers, however, are often hard 
to see; therefore, we often see them growing in 
groups. Lilacs are groups of flowers, and you 
know how easily seen they are. The bridal- 
wreath which blooms on bushes in our gardens 
in early spring is another example. So is the 
hyacinth. You can see the separate small flowers 
very readily. This group arrangement has two 
advantages—the flower can be seen better, and 
the insect can pollinate a large number of seeds 
at one time. 

Some flowers are so small that we think of 
the whole group as just one flower. Clover is 


FRIENDS AND ENEMIES 


an example of this kind. Did you ever notice 
that one clover blossom is made of dozens of 
tiny flowers? If you haven’t, pull one apart the 
next time you have a chance and you will see 
them. Bees love clover because of its sweet nec¬ 
tar, but they could never find it if these tiny 
flowers grew by themselves. Because they 
have clubbed together into a good-sized group, 
the bee has no trouble whatever in finding them. 

There is another family which has even 
smaller flowers. These flowers are so tiny that 
most people never think of them at all but say 
that a daisy is a flower, or that a dandelion is a 
flower. It is more correct to say, “A daisy is a 
great many flowers growing on one head.” If 
you take a daisy apart, you will find two kinds 
of flowers. Each one of the outside petals is 
nearly a complete flower all by itself. It has 
one big petal and a pistil, which is the part that 
holds the baby seed. It usually does not have 
any stamens; and so it has to get pollen from 
other flowers. The inside, or heart, of the daisy 
has hundreds of tiny flowers. They do not 



Clover is made 
of many 
blossoms 



3 2 


THE GARDEN OF THE WORLD 


have big petals, and are so small and yellow 
that many people think they are just stamens. 
When they are magnified, however, each is seen 
to be a tube of small petals, containing a pistil 
and some stamens. All of the parts needed to 
pollinate the seeds are there. Try to imagine, 
though, what a hard time such a little flower 
would have growing by itself. A bee would 
never see it, for it is no bigger than a bee’s leg. 

The plant put all these small flowers on one 
big head which is bright and showy. The two 
kinds of flowers that make a daisy have their 
own separate work to do. The outside flowers 
with the large petals are called “ray flowers” 
because they stand out like the rays of the sun. 
The smaller, inside ones are called “disk 
flowers,” because they grow on a round, flat 
disk. The ray flowers are the most attractive. 
They tell the bees that here is a blossom with 
pollen and nectar for them. The disk flowers 
are the workers. They produce the seeds. The 
ray flowers are able to have seeds, but usually 
they do not. 


FRIENDS AND ENEMIES 


33 


The dandelion is another plant which has a 
head made up of many flowers. You can tell 
how many flowers there have been when the 
seeds are ripe and ready to blow away. Every 



The clover, dandelion, daisy, and many other 
common flowers are really many flowers in one 

seed stands for a flower. Sometimes there 
are as many as two hundred flowers on the 
head of one dandelion. 

Plants which have heads holding many small 
flowers belong to the Composite family. Many 



34 


THE GARDEN OF THE WORLD 


Why do flowers 
open and close? 


of our commonest flowers belong to this family. 
Besides the daisies and dandelions, there are the 
sunflowers, brown-eyed susans, dahlias, chrys¬ 
anthemums, and thistles. 

Flowers close to keep out the rain, to keep 
warm, and to keep unwelcome insects away 
from their pollen. They stay open during the 
business hours of the insects they favor. If bees 
and butterflies are wanted, the flower is open in 
the daytime when these insects are flying. It 
closes at night to protect its nectar from the rain 
and dew. The flowers which prefer moths, 
however, are open at night and closed in the 
daytime because moths fly at night. 

About four o’clock in the afternoon, the 
small flowers of the white honeysuckle begin to 
open, and the sweet fragrance becomes very 
strong. Soon the sphinx moth, attracted by 
the perfume, begins to hover over the blossoms. 
It is a large moth and resembles a humming bird 
when flying. It has a long tongue which it 
carries rolled up. At each honeysuckle this 
tongue is unrolled and thrust deep into the 


FRIENDS AND ENEMIES 


35 


flower for a long drink of nectar. At the same 
time the moth dusts off onto its body some of 
the pollen, which it carries to the next blossom. 
It takes a great many honeysuckles to satisfy a 
thirsty sphinx moth. It flies about all night, 
guided by the perfume of the flowers, and by 
their white color. 

White shows up much more plainly at night 
than red or other colors. That is why more 
white flowers than any other color smell sweet. 
They are designed to attract night flying insects. 
Sometimes the moths do not get to all the 
flowers before morning. The honeysuckles 
that have been pollinated turn yellow and close 
as a sign that they do not need any more visitors. 
The ones which have not been visited by the 
moths stay open for a time in the morning to 
let the bees and the butterflies do what they can. 
They come around anyway to get what is left. 
If the night has been clear and calm, they will 
not find much nectar or pollen because the 
moths have taken it all, but if the night was 
stormy, the moths would have had to find 


36 THE GARDEN OF THE WORLD 

shelter from the wind and rain, and the bees 
may have a feast. 

The Jimson weed also waits for four o’clock 
to entertain the sphinx moth because its nectar 
tubes are too long and narrow for any other 
insect to reach. Sometimes it opens early and 
the bees come and take the pollen. 

The beautiful evening primrose stays closed 
all day to protect its pollen from bees and flies, 
for it is also waiting for the sphinx moth. If 
the moth misses a flower, that flower stays open 
in the morning until a bumblebee visits it. It 
must be pollinated at once because its petals last 
only one day. 

There is a family of blossoms called the Catch- 
flies. The night blooming catchfly is a pale 
pink and has a sweet perfume to attract the 
moths. The day blooming catchfly has no 
odor at all, but has bright colors to guide the 
butterflies which fly by day. 

On the whole, colored flowers bloom by day 
and close at night, while white flowers open at 
night and have the sweetest perfume. There 


FRIENDS AND ENEMIES 


37 


are exceptions, to be sure, but this is the general 
rule which the flowers follow. 

Have you ever noticed how many red flowers 
have their nectar hidden in deep slender 
pockets? If you want to suck the nectar, you 
must bite off the end of a tube and get it from 
the bottom for, of course, your tongue is too 
thick to get into the narrow opening. The 
bumble-bee’s tongue is narrow but not long 
enough. At least a dozen red colored flowers 
are made this way: the trumpet flower, the coral 
honey-suckle, the red and yellow columbine, 
jewel weed, bee balm, gladiolus, canna, nastur¬ 
tium, and salvia are some of them. 

Red seems to be the favorite color of the hum¬ 
ming bird. These red flowers are saving their 
nectar for him. His long, sharp bill is just the 
right size and shape to fit into their nectar 
tubes. They bloom later in the summer than 
the blue and yellow flowers as a rule, because 
the humming bird does not come as early as 
the bees. To be sure, many of the flowers wait 
in vain, because humming birds are not very 


Why do so many 
red -flowers have 
long narrow 
tubes? 


38 


THE GARDEN OF THE WORLD 


common. Often times not one comes to a 
garden in a whole season. These red flowers 
would not get their seeds pollinated if the bees 



The humming-bird's bill is the right shape to 
reach the nectar of certain flowers 


and butterflies did not help them out. These 
insects cannot get to the nectar, but they are 
never tired of trying, and there is plenty of 
pollen to reward them. 

Sometimes the humming birds do come, 
however. If they are anywhere in the neigh¬ 
borhood, a garden with red flowers is sure to 





FRIENDS AND ENEMIES 


39 


attract them. Some people plant trumpet vine 
and coral honeysuckle just to entice them. If 
they do come they dash from one flower to an¬ 
other in a perfect frenzy of joy. Their little 
wings beat so fast they seem to be just a blur in 
the air. Their sharp little beaks find the nectar 
in a second and drain every drop. They do 
not care for pollen as the bees do, but, of course, 
it sticks to them anyway, and they carry it to 
other flowers to pollinate them. 

Crawling insects, like ants, usually are 
enemies to plants, while flying insects, like bees 
and wasps, are friends. A plant’s problem is 
to make the flying insects welcome and at the 
same time keep out the crawlers. The crawl¬ 
ers are enemies because they eat the pollen and 
drink the nectar but do not carry the pollen to 
the other flowers. It is easy to see that by the 
time an ant crawled all the way down the stem 
of a rose-bush and up another stem to another 
rose, the little bit of pollen that had clung to 
him would be brushed off. A bee, on the other 
hand, flies in the air from one flower to another 


How do plants 
protect them¬ 
selves? 


4 o 


THE GARDEN OF THE WORLD 


so quickly that she cannot help but carry the 
pollen. It is the flower’s business to see that 
its pollen is carried to another flower, and nature 
provides a means to prevent any insect that in¬ 
terferes with that business from taking the 
pollen and nectar. If ants get into the flower 
first, there will be no pollen left for the bees 
and butterflies; so the ants must be kept out. 

Some flowers, like roses, have many fine hairs 
along their stems that keep an ant from crawl¬ 
ing up. As she goes up the hairs keep getting 
thicker and thicker. They are like a forest to 
her; so she gives up. The hairs near the top 
are smeared with a gummy juice which hold 
her legs. It is just about impossible for an ant 
to get to a rose. 

Milkweed juice is useful against ants, too. 
The skin of a milkweed stem is very thin. As 
the ant crawls up, her sharp feet cut through 
the thin skin and start the milky juice to flow¬ 
ing. Her feet become wet and tangled. If 
she is wise she will drop off immediately while 
she still can. If she keeps on trying to get up, 


FRIENDS AND ENEMIES 41 

the juice hardens and holds her so fast that 
she can never get away. 

The wild pink punishes crawling insects who 
try to steal nectar by catching them in a sticky 
juice smeared high on their stems. It holds 
them as fast as fly paper does. Perhaps you 
have noticed certain weeds that made your 
fingers sticky when you picked them. This is 
the reason for that stickiness. 

Some plants must protect themselves from ^ 
cattle who would eat their leaves before the 
season’s work is done. Roses and nearly all g 
plants of the Rose family have sharp thorns 
that give a sharp prick to any cow who tries to r 
take a mouthful. Wild parsnip which grows 
in the fields has a sour juice that causes the cattle 
to leave it alone. Some weeds have poisonous ^ 
leaves that make the cattle sick or kill them, if ^ 
eaten. Cattle soon learn to leave these plants 
alone and not to molest them. 

Did you ever look inside of a burr? If cut 
across with a sharp knife, the seeds are found 
inside. The parent plant must have those seeds 

Roses protect them¬ 
selves from crawlers 


4 2 


THE GARDEN OF THE WORLD 


planted somewhere so that they can grow. The 
burdock, a plant that produces burrs, usually 
Why do burrs grows in thick patches. The space is crowded 
stiC k? with plants, and there isn’t much space for new 

ones. The plant provides that its offspring 
gets far away and starts life in a new place, 



The many different \inds of burrs have just one 
purpose—to be carried somewhere 


where there is not so much struggle for light 
and ground space and moisture. Its way of 
accomplishing this is to have little hooks on its 
seed pods. When a boy and his dog run through 




FRIENDS AND ENEMIES 


43 


the prairie, some of the little burrs hook onto 
the boy’s stockings, and others catch on the 
dog’s hair. Later on the boy pulls the burrs 
off. Perhaps he will pull them off the dog too. 
If he doesn’t, the dog will have to bite them off, 
for they are sure to bother him. If the burrs 
happen to drop on the ground in a good place, 
they will take root and begin to grow, not right 
away, of course, but the next spring. If they 
are taken off in the house or drop on the side¬ 
walk, they are lost. The parent plant makes 
provision for many of its seeds being lost; so it 
produces a great many more than ever can grow. 
That is why each burdock plant has such big 
bunches of burrs. 

The burdock is not the only plant that sends 
out its seeds in this way. There is the cockle- 
bur. That is the plant with the good-sized 
burr which has a great many rather fine spikes. 
The burdock burr is smaller, with a few heavier, 
sharp-pointed hooks. The cocklebur is the 
kind that children often put together in big 


Burrs travel a 
long way 









44 


THE GARDEN OF THE WORLD 


bunches or even use in modeling doll furniture 
and crude little figures. Another common 
plant with prickly seeds is the Spanish Needle. 
It has a single seed with two sharp points that 
are hooked. Sometimes one person will have 
as many as a hundred of them sticking to him 
at one time. The wild animals help distribute 
these seeds even more than people or dogs. 
They live in the places where these wild plants 
grow and they can carry an enormous number 
of burrs in their shaggy coats. Sometimes an 
animal, such as a squirrel or rabbit, or even a 
fox, will carry them for a long distance before 
he can get rid of them. In this way the new 
plant has a chance to find a good growing place, 
far from home. 

And so burrs stick so that the seeds which 
they hold may be carried away from their parent 
plant to a new place which will be a good one 
for the new plant to make a start. 


Chapter III 


SUNLIGHT FACTORIES 

V INES climb in order to get their leaves 
into a better place in the sunlight. They 
have many ways of getting up from the ground. 
Some vines twine their stems about a support 
such as a fence rail, a stick, a bush, or a tree. A 
curious thing about these twining plants is that 
they always twist in the same direction. The 
hop vine winds from right to left, or with the 
sun. The morning glory always goes against 
the sun, or from left to right. 

The cucumber and grape vine have tendrils. 
These look like short stems, but they do not 
have leaves. The ends of the tendrils are 
hooked, and they coil when they strike a sup¬ 
port. Sometimes a real stem acts as a tendril. 
It curls about a support and then continues on 
its way, bearing leaves as it goes. The Boston 

45 


How do plants 
climb? 


4 6 


THE GARDEN OF THE WORLD 




ivy has tendrils also, but at their tips the tendrils 
have sensitive disks which give off a sticky juice 
when rubbed against a support. This juice is 
like glue and fastens the tendril very tightly. 

Other plants—the trumpet vine, the poison 
ivy, and the English ivy—have aerial roots 
which attach themselves to the support. They 
like best to climb a brick or stone wall and these 
roots occupy the chinks or dark places of the 
wall or of the bark if they are climbing upon 
the trunk of a tree. 

Some plants just scramble up. The tall 
blackberry has hooks and prickles all over its 
stems and leaves which hold fast to any support 
they may happen to find. 

Climbers can get very high into the air with¬ 
out wasting effort in building strong stout 
trunks as trees do. They can get a great many 
leaves to the light and can grow very swiftly. 
Many of them have very long stems, from fifty 
to three hundred feet long. In the hot damp 
countries there are vines with stems as long as 
one thousand feet, which is nearly a fifth of a 

Climbers have 

different 

methods 


SUNLIGHT FACTORIES 


47 


mile. Vines have one disadvantage. If they do 
not find a support, they cannot get their leaves 
into the light and as a result, they do not thrive 
so well. Climbing plants sometimes put on so 
many leaves that they shade the tree or bush 
they are leaning upon and injure it, and some¬ 
times even kill it by keeping the sunshine away. 

Plants are like people in a great many re¬ 
spects, but in one way they are much more 
independent, for they can make their own food. 
Each plant, big and small, is a busy food 
factory, and the busiest workshop in the factory 
is the leaf. Whenever you see green leaves on a 
tree you may know that they are working hard 
at manufacturing food that will keep the tree 
alive and make it grow tall and strong. Let us 
take, for example, an oak leaf and see what 
happens in its workshop. 

The first thing the leaf needs is water, and 
the veins which you have often noticed bring 
that. The water gets into the trees through the 
roots. It travels up the tree trunk through long 
narrow tubes which are connected to the veins. 

Morning 
glories must 
have a support 


How do plants 
get their food? 




4 8 THE GARDEN OF THE WORLD 

The arrangement is something like the water 
pipes in a house. The water comes in at the 
basement, is brought upstairs through large 
pipes, and is passed on to many small pipes so 
that we may draw the water out of the faucets 
in several different rooms. 

The next thing the leaf needs is carbon 
dioxide. Carbon dioxide is very familiar to 
you, although you may not know it by name. 
When you breathe you must have oxygen, but 
the air you breathe out is carbon dioxide. It is 
not good for human beings, and if there is too 
much in the room it makes us sick. That is 
why we need to have our windows opened and 
why we say, “We must have some fresh air.” 
A plant, however, is just the opposite from 
people for it breathes in carbon dioxide and 
breathes out oxygen. A leaf breathes through 
little holes on the under side of its surface. You 
cannot see them without a microscope. 

A green leaf has the ability to take this water 
and carbon dioxide and put them together. The 
result is sugar, because sugar is made of carbon, 


SUNLIGHT FACTORIES 


49 


oxygen, and hydrogen. Carbon dioxide is made 
of carbon and oxygen, and water is made of 
oxygen and hydrogen. You can see that there 
will be some oxygen left over; so the leaf 
breathes this out. This sugar is what the plant 
needs for food. It is sent all over the plant 
through slender tubes. We get our sugar from 
plants that make more than they can use—the 
sugar cane and sugar beets, for example. 

The leaf can only make food when the sun 
is shining and the weather is warm. That is 
one reason why leaves drop off in autumn. 
They cannot work in winter, so the tree rests. 
The leaves do not work at night, either, because 
there is no sun. The tree must have food all 
winter, even if it isn’t working, and it must 
have some stored up to use in the spring until 
its leaf factory has a good start. Therefore the 
tree stores away some food, just as the squirrels 
store away nuts. It wouldn’t be a good idea to 
store the sugar because it dissolves in water and 
would soon be lost. Most plants have the power 
to change sugar into starch. The starch does 


5 ° 


THE GARDEN OF THE WORLD 



not dissolve in water so it will keep a long time. 
We often eat the starch that a plant has stored 
away. We do this when we eat potatoes, corn, 
and many other foods. Different plants store 
their winter food in different places. The trees 
store theirs in the roots and trunk. Potatoes 
are special storage rooms attached to the roots 
of the potato plant. Corn and wheat store their 
starch in the seeds because they are plants that 
live only one year, and the seed needs, some food 
to start on in the spring. 

The leaf factory can only work in the sun¬ 
shine. That is why house plants should be near 
a window and why grass will not grow under 
a big tree which cuts off the light. Because 
light is needed this process of food making is 
called photosynthesis (pronounced fo'to-sin'- 
the-sis). Photo means light. It is the same 
Greek word that is found in photograph. 
Synthesis means “putting together.” The whole 
word means “putting together by means of 
light.” That is just what the leaf does. It puts 
water and carbon dioxide together when the 
sun is shining. 


Leaves are 
factories word¬ 
ing in the sun 












SUNLIGHT FACTORIES 


5 1 


Only an expert can tell the age of living trees 
unless they are pines or spruces. Anyone can 
count the circles of branches on these trees. If 
there are ten rows, the tree will be ten years 
old. But anyone with sharp eyes can tell the 
age of a tree that has been cut down by 
counting the rings in the end of the log. Each 
ring stands for a year’s growth. The part 
nearest the center of the log is the oldest, and 
that nearest the bark is the newest. The grow¬ 
ing part of the tree is just under the bark. It 
is called the cambium (pronounced kam'- 
bi-um). The working parts of the tree trunk 
are near here also. Next to the cambium, on 
the inside, are the tissues that carry water up the 
tree. On the outside of the cambium, nearest 
to the bark, are the tissues that carry the food 
from the leaves to any part of the tree that needs 
it. All during the growing season, the cam¬ 
bium works very hard, forming new water¬ 
carrying and food-carrying tissues. Mixed with 
the water carriers are wood fibers also. Some¬ 
times the trunk becomes so much larger that it 

The age of a tree can 
om the stump 


How can we tell 
the age of trees? 










52 


THE GARDEN OF THE WORLD 


is too big for the bark. The bark stretches and 
stretches and finally cracks. That is why bark 
is so rough and has such deep furrows. 

As the summer comes to an end, the cam¬ 
bium, or growing part, grows more and more 
slowly, and when cold weather comes it stops 
altogether. This slowing up is easily seen at 
the outer edge of the ring as the wood has a 
different appearance. It is that which shows 
clearly the end of one year’s growth and the 
beginning of the next. The ring of wood 
formed during a favorable season—that is, a 
spring and summer with plenty of rain and 
sunshine—is wide. If the season was too dry, 
the ring is narrow. Just as each summer is 
different from the last one, so each ring differs 
from every other. Men who have had a great 
deal of experience in examining annual rings 
can tell what kind of weather there was during 
a certain year by looking at the rings. This is 
very useful when studying extremely old trees 
such as the big trees of California. These trees 
are so very old that they were growing before 


SUNLIGHT FACTORIES 


53 


any of our American history was written, or 
indeed, even thought of. But experts can tell 
something about the weather five hundred or 
a thousand years ago by examining the logs. A 
ring that is very thin means a dry season. A 
wide one means a rainy year. Several narrow 
ones close together mean there was a period of 
dry weather lasting for some years. Many of 
these huge trees have over a thousand rings, 
showing that they are over a thousand years old. 
Most of the logs cut down for lumber from the 
pine and oak forests have from thirty to one 
hundred rings. Some of these trees, however, 
are even younger. 

As the outer rings of the tree continue to 
grow, the inner ones die. They do not carry 
sap or water any more, but they do not decay 
unless they are diseased. Oftentimes only the 
outer three or four rings are alive. The outer 
living part is called the sapwood, and the inner 
dead part is the heartwood. The heartwood 
changes color and is usually darker and more 
beautiful. It still serves to support the heavy 


T he rings 
of the tree 
tell its age 



54 


THE GARDEN OF THE WORLD 


How do roots 
wor\? 


tree, and because of its rich color it is more 
desirable for lumber than the sapwood. 

Roots have two jobs. One is to serve as an 
anchor and hold the plant firmly in the ground. 
The other is to absorb moisture and mineral 
substances from the soil. A plant requires a 
great deal of water, getting nearly all of it from 
the roots. The rain which falls upon the leaves 
is not particularly useful to it. 

There are almost as many different kinds of 
root forms as there are kinds of plants. One 
reason for these different forms is the place 
where, the plant is growing. A corn plant living 
in sandy soil will have deeper, longer roots than 
one growing in heavy black soil because the 
water soaks into sand more quickly and the 
roots must reach further to get it. 

A carrot is a root. When one that has just 
been pulled from the ground is examined, it is 
easy to see the many fine hairs growing out from 
the sides. These are called root hairs, and they 
do most of the work of absorbing moisture. 
They soak up every drop of water they touch 


SUNLIGHT FACTORIES 


55 


and pass it back to the main root—in this case 
the carrot. The main root has water-carrying 
tissues like a stem, and it sends the water up to 
the leaves. A root like a carrot is called a tap 
root because it goes straight down into the 
ground and “taps” the water supply. The dan¬ 
delion has this kind of root also. This is an 
interesting one to study because it usually has 
many more root hairs than the carrot. The tap 
root of the dandelion is much larger also. In 
roots of this kind the long thick part is chiefly 
for holding the plant in the ground and taking 
care of stored up food, while the root hairs 
absorb the water. These root hairs then pass 
this water back to the main root. 

Most smaller plants have a crooked, branched 
root that looks like a stem, and each branch has 
many hundreds of root hairs. These root sys¬ 
tems are of all sizes and shapes. Some of them 
are very shallow in order to get the rain from 
the surface of the ground. These do not make 
very good anchors and their plants are easily 
blown over. Roots like this are very satisfactory 




There are many dif¬ 
ferent root forms 









56 


THE GARDEN OF THE WORLD 


in places where the rain falls often and the 
surface of the earth is always moist. 

Where the soil is sandy or coarse, and rain 
falls only occasionally, the roots must go deeper 
into the ground because the water does not stay 
on the surface but soaks in. Sometimes it goes 
down several feet until a bed of clay or rock 
holds it. There it lies until it has been used up 
for there is no air to make it evaporate. Plants 
which grow in very dry places often have root 
systems many times larger than the plants them¬ 
selves. They branch out sideways in every di¬ 
rection and go deep down into the earth as well. 
They must be sure of getting every drop of the 
precious water when there is any. The prickly 
pear cactus, for example, often has roots that 
extend at least five feet on each side. 

Trees, of course, must have very big roots to 
make a firm support for the heavy weight of the 
tree. A tree needs an enormous amount of 
water; so the roots branch out in all directions 
and especially go deep down into the earth to 
get all of the moisture possible. The big 


SUNLIGHT FACTORIES 


57 


and the smaller ones divide and redivide. All 
of the smaller ones are covered with root hairs. 
Just as with the smaller plants, it is the root hairs 
that do the real work of absorbing moisture 
from the soil. 

When a tree is dug up, or a tree in the woods 
has been blown over, it is easy to see what a 
twisted network of branches there is under 
ground. The root hairs are plainly seen. It is 
interesting to think how important these tiny 
fibers are to the life of a big tree. 


A tree's roots 
must reach far 
in the ground 






Chapter IV 


Why is it hard to 
grow flowers in 
the shade of a 
tree? 


FOOD FOR PLANTS 

li^TOST flowers will not grow well in the 
shade because there is not enough light 
for the leaves. Leaves cannot manufacture food 
unless there is plenty of sunlight. The leaves of 
the tree form such a heavy shade that no sun¬ 
light gets to the little plants underneath. But 
some plants come up early in the spring and 
get all their work done before the trees have all 
their leaves. That is why violets, lilies of the 
valley, blue phlox, and spring beauties can grow 
in shady places. 

A second reason is because the drip of water 
from the branches of the trees washes away the 
soil from the plants that are growing below. 
But a third and more important reason is be¬ 
cause the plants are likely to starve to death. 
All plants must have some minerals and other 

58 


FOOD FOR PLANTS 


59 


plant foods which they get from the soil. A 
tree is such a big thing that it needs an enormous 
amount of food. It sends its roots out a great 
distance on all sides in search of nourishment. 

These roots are so greedy that they do not leave 
anything in the soil for the other plants. Smaller 
plants can be helped by using fertilizer. It 
supplies the minerals which plants need. We 
must use a generous amount of fertilizer in 
shady places because, of course, the tree will 
take some of that too. A good dose of bone 
meal once a year will do a great deal for plants 
that are struggling to grow in shady places. 

All honest plants make their own food and wh at p i ants are 
can be told by their green leaves. The plants pirates? 
which steal their food are pirates and have lost 
their green color. There are not a great many 
of these pirates or parasites as they are called. 

The mistletoe, which grows in the southern 
states, is one of these dishonest plants. It drops 
its seeds on the bark of trees and, instead of 
sending its roots into the ground as any honest 
plant would do, it sends them into the tree, 


6o 


THE GARDEN OF THE WORLD 


where they soak up the food the tree has made 
for its own use. The mistletoe, however, is not 
entirely a bandit for its leaves are a dull green. 
This means that it does make a little of its own 
food, but it steals the moisture which it uses 
from the tree instead of absorbing it from the 
earth as the tree does. 

The most interesting of the pirate plants is 
the Indian Pipe. This little plant is found 
growing in damp, shady places in the woods 
where the leaf mold is very thick and black. It 
is only a small plant, six or eight inches tall, but 
it sometimes startles one because it is so white 
and ghostlike. It is colorless, cold-looking, and 
clammy to feel. It has not one speck of honest 
green color but it does have a ghostly charm. It 
has tall, straight stems and flowers that bend 
over at the top, giving it a shape something like 
the pipes the Indians used for smoking. It lives 
on the juices of living plants or the decaying 
matter of dead ones. Because it does not work, 
it does not need sunshine and is found in the 
darkest places. It is easily seen because its 


FOOD FOR PLANTS 


61 


whiteness is such a contrast to the black, decayed 
leaves that are its favorite home. 

Another parasite plant is the Dodder. It is 
a gold colored vine, and so is often called the 
Golden Dodder. It is really a pretty plant with 
small pink flowers. Its slender stems wind 
themselves around tall plants and bushes like 
golden threads. It sends many rootlike suckers 
into the bark to steal food. It doesn’t have a 
single leaf and not even a root after it has passed 
the seedling stage. Its little suckers look like 
roots, but they are not. They are just what their 
name says—suckers. They suck food and water 
from the other plant from which the Dodder 
is stealing its food. 

There are three common plants which grow 
in our country—the pitcher plant, sundew, and 
bladderwort—which trap their food. Their 
victims are small insects. 

The pitcher plant, which grows in bogs and 
swampy places, is a sturdy good-sized plant. Its 
leaves are shaped exactly like pitchers, except 
that there is no handle. They are often several 

The dodder does not 
even have a root 



62 


THE GARDEN OF THE WORLD 


inches long. There is even a spout at the top. 
This pitcher is usually half full of water; some 
What plants trap of it is rain; some is juice made by the leaves. 
their food? The j u i ce k as an 0 ( j or attrac tiv e to insects, and 

they step in to see what they can find. But they 
never come back! The walls of the pitcher are 
steep and slippery and it is impossible to crawl 
up them. The insect’s dip into the water has 
made its wings so wet that it cannot fly. Even 
if it could fly to the top, there are strong hairs 
which prevent escape from the opening. There 
is nothing for the insect to do but drop back and 
drown. One of these pitchers will often con¬ 
tain many gnats, mosquitoes and flies, and a few 
beetles. In California there are pitchers large 
enough to drown a mouse. 

Why does this plant trap the insects? Be¬ 
cause it needs nitrogen. All plants must have 
nitrogen, but most of them get it from the 
soil. When our garden plants are not getting 
enough, fertilizer must be put on the ground to 
help them out. Human beings need nitrogen, 
too, but we get it from meat and eggs. The soil 


FOOD FOR PLANTS 


63 


where the pitcher plant lives is very poor in 
nitrogen, so it has to get it in some way. De¬ 
caying animal matter contains a great deal of 
nitrogen and so the pitcher plant captures these 
small animals, waits until their bodies decay, 
and then uses the nitrogen. 

Our second trapper is the sundew. It is a 
pretty, innocent-looking plant that gets its name 
because its leaves glisten in the sun as if they 
were covered with dew. Sometimes they look 
as if the dew had frozen on them. That shiny 
surface, however, is deadly to insects for it is very 
sticky. A fly alights on the leaf and finds his 
legs are caught in the glue. The more he 
struggles to get free, the tighter he sticks, for he 
becomes plastered all over with this sticky juice. 
It catches him just as surely as sticky fly paper 
does. Now the leaf rolls up around him and 
digests him just as if it were a little stomach. In 
this way the plant gets its nitrogen, as we get 
ours by digesting food that contains nitrogen. 

The bladderwort is another trapper. It is a 
floating plant and lives in the water. At the 


Some plants 
have to trap 
part of their 
food 





6 4 


THE GARDEN OF THE WORLD 


Why is clover 
good for the 
grass? 


tips of its leaves are little bladders or bags. Each 
bladder has a remarkable little trap door at the 
end of it. This door opens at a touch from the 
outside, but will not open at all from within. 
Tiny water creatures brush against the trap door 
and instantly find themselves inside the bladder. 
There is no-escape possible, so they die and then 
decay to be used as plant food. The bladder- 
wort catches only tiny creatures. Some of them 
are so small that a strong magnifying glass is 
needed to see them at all. 

Long before anyone knew the reason, gar¬ 
deners and farmers knew that clover was good 
for the soil. A farmer found that if he had a 
field of clover one year and planted corn the 
next year, his corn would be better in that field 
than in any other. The reason is interesting. 
Next to carbon dioxide and water, the most 
important element that plants need is nitrogen. 
Nitrogen is very plentiful in the air. It is about 
us all the time, but unfortunately plants cannot 
use it in that form. They can only get it when 
it is in the soil combined with other elements. 


FOOD FOR PLANTS 65 

These combinations are called nitrates. Nitrates 
can be bought to use for fertilizer, but they are 
expensive. There is only one kind of plant that 
can use nitrogen from the air, and it is a family 
of bacteria that live on clover roots. When a 
full grown clover plant is pulled up, roots and 
all, many little lumps can be seen clinging to the 
roots. These lumps are full of bacteria, so small 
that a microscope is needed to see them at all. 

This one kind of bacteria can take nitrogen 
from the air and combine it with other elements 
from the soil to form nitrates. They leave these 
nitrates in the earth, and after the clover crop 
is cut down, the nitrates remain there for other 
plants to use. These bacteria only live on the 
roots of clover or the roots of other plants of 
the clover family. 

If grass is not growing well, it is a good idea 
to plant clover. One planting of clover will 
enrich the soil enough to last for several seasons. 
Other members of the same family that are 
good for the soil are peas, beans, and alfalfa. 
Wherever these plants have been growing, the 


66 


THE GARDEN OF THE WORLD 


Why do dande¬ 
lions \ill the 
grass? 


soil is much better because of the nitrates left in 
it by the nitrogen-using bacteria which live on 
the roots. Farmers should plant their fields to 
clover once every few years to keep the soil rich. 
They should do this especially if they raise corn, 
for corn is hard on the soil, and if grown too 
many years in succession, will not give a good 
crop. All up-to-date farmers alternate clover 
with corn or wheat. This method of keeping 
the soil rich is called “rotation of crops.” 

The dandelion is a great nuisance to the 
gardener. He fights it all summer long, and 
usually he finds at the end that the dandelion 
has won the battle for it is a very good fighter. 
If beaten in one way, it will come back in an¬ 
other. Cut off its leaves; it sends up some new 
ones. Cut off the root; it starts growing at the 
cut place. Pull it up by the roots; and if every 
bit of it comes up, which hardly ever happens, 
this one is conquered. But by this time it has 
sent out hundreds of seeds; so next year it will 
be even harder. 

The dandelion has many good weapons with 


FOOD FOR PLANTS 


67 


which to fight. First, it has a long strong root 
which goes so deep into the ground that the 
frost cannot hurt it. It is too deep for rabbits 
and moles to chew, and too strong for insects 
to bother. It has a circle of strong green leaves. 
These are arranged in a rosette so that they get 
the most possible sunlight. Notice how the 
dandelion leaves lie flat and are arranged so that 
none of them shades any other. The leaves are 
so close to the ground that no plant can get 
underneath and steal food from the soil. They 
make it so dark under them that any grass 
which was there before has to die for lack of 
sunshine. If the rosette of leaves begins to get 
too tall, the root pulls it down closer to the 
earth. The flower stem is hollow. Engineers 
know that a hollow tube is much stronger in 
many ways than a solid one. Hollow steel tubes 
are used in many places where lightness and 
strength are needed. The dandelion stem is so 
light and yielding that it may be bent way over 
without hurting it. Yet it is so strong that the 
hardest wind storm will not break it. Finally, 



The dandelion 
has many 
weapons 


1 1 
\ 


68 


THE GARDEN OF THE WORLD 


it has the best system in the world for raising 
flowers. Each dandelion blossom is composed 
of many tiny flowers and each one produces a 
seed. After a dandelion has gone to seed it 
grows taller. This is so the breeze will be sure 
to get to the seeds and blow them far away to 
begin new homes. 

Is it any wonder that we cannot get rid of 
dandelions? From the point of view of man 
this little yellow flower is a pest, but from the 
point of view of plants it is most successful. Its 
roots, stem, leaves and flowers all work together 
to see that the dandelion has the best of every¬ 
thing. We call such working together, effi¬ 
ciency, and the dandelion is the most efficient 
plant in the whole plant kingdom. 


Chapter V 


STORAGE ROOMS 


V EGETABLES are really any part of the 
plant that is eaten, but the word usually 
means parts that are not sweet. Oranges, 
apples, and bananas are sweet and so are not 
called vegetables. Some fruits are vegetables, 
but all vegetables are not fruits. The difference 
will be seen later. Vegetables are good to eat 
because the plants have stored up food in them. 
Different plants choose different places to store 
food; vegetables, therefore, come from six parts 
of the plant. 

i. Tubers are thickened branches of an 
underground stem. The most common ex¬ 
ample is the white potato. It is good to eat 
because it is full of starch, which is one of the 
substances needed to give us heat and energy. 
2. Roots give us many of our vegetables: 


Potatoes 
are tubers 


What are 
vegetables? 



7 ° 


THE GARDEN OF THE WORLD 


radishes, turnips, beets, sweet potatoes, parsnips, 
and carrots. Root vegetables do not have as 
much starch as tubers, but they contain many 
mineral salts which people must have, and they 
are coarse and rough. We cannot get along 
with only soft, tender food. 

3. Bulbs give us only one common vegetable 
—the onion. A bulb is an underground bud 
that is full of food to help the young plant to 
grow quickly. The food is just as good for 
human beings as for the young plant. 



4. Leaves give us some of our most healthful 
vegetables, for although they do not contain 
much starch, they are full of minerals, vitamins, 
and supply the coarseness which we need. Spin¬ 
ach is the most common leaf food. Cabbage, 
lettuce, and celery are also leaf foods, although 
most of the stalk is eaten too. 

5. Bruits which are not especially sweet are 
also called vegetables. Tomatoes, pumpkins, 
cucumbers, and squash are all fruits. They are 

he water and minerals 



A common 
bulb, leaf, 
and fruit 





STORAGE ROOMS 


7 * 


6. Seeds give us three of our most useful 
vegetables: peas, beans, and sweet corn. They 
supply starch and some fats. The peas and 
beans also have proteins, the substance needed 
for growing. They can take the place of meat 
because protein is the substance supplied to our 
bodies by meat. 

Leaves are the workshops of the plant. A 
peculiar green substance, chlorophyll, makes it 
possible for them to manufacture food. They 
absorb water from the roots and carbon dioxide 
from the air. Water is very necessary to the 
making of food. But, in addition, more water 
is needed by the leaves than is used in photo¬ 
synthesis. In order to work properly the cells 
of the leaf must be full of water. When a leaf 
wilts, it is because the cells are nearly dry. 
Water is also needed to carry the finished food 
from place to place in the plant. Therefore, 
the leaves are constantly calling for more water. 
They draw up more than they need. There are 
tiny openings in the under side of the leaves 
where the extra water may escape. The mois- 


Why do leaves 
drop in the 
autumn? 




Many seeds are 
good to eat 











72 


THE GARDEN OF THE WORLD 


ture evaporates into the air just as the damp¬ 
ness evaporates from a wet rag that is hung on 
a clothesline. This process of giving off mois¬ 
ture is called transpiration. It is very like 
perspiration. It keeps the leaves cool, just as 
perspiration keeps human skins cool on a hot 
day in summer. 

Now, leaves, of course, cannot think and do 
not know anything about outside conditions. 
Their job is to bring up water for food making 
and get rid of what is left over. They are not 
able to know whether water is plentiful or 
scarce; the small pores open and pass off the 
moisture just the same. This is very hard on 
the plant during the dry season, for often it 
cannot get any moisture and the whole plant 
wilts. All the cells of the plant must be full of 
water, not just the leaf cells only. It is not at 
all unusual for delicate plants to die during a 
drought because the leaves transpire too much 
of the water the plant must have. 

Trees must be very careful of their water 
supply because they are so large that they use a 


STORAGE ROOMS 


73 


great deal. They have a special arrangement 
to prevent too much transpiration. The leaves 
can make food only during the warm sunny 
months. As the weather gets colder, they work 
more and more slowly, and at last stop alto¬ 
gether. Even though they are not working 
they continue to send off water. Moisture is 
scarce in cold weather and the tree cannot afford 
to lose any. In order to save its precious water 
supply, the tree drops its leaves. During the 
winter the tree can get along better without 
them because they do not work, and they are 
wasteful of moisture. When they are gone, 
most of the water is safe. It cannot escape in 
any other way. The bark is too thick and 
rough to allow any moisture to pass through. 
When spring comes again with its rain, new 
leaves come out and carry on the work of 
making and transpiring moisture. 

The chief business of a flower is to produce 
seeds, to see that they are safely pollinated and 
ripened in order that they can grow into new 
plants. The parent plant takes great care to 

Trees drop 
their leaves 
to save water 

















74 


THE GARDEN OF THE WORLD 


What is a seed? 


see that the seed is given a good start in life. 
First of all, the seed has a hard outside coat. 
This is strong enough to protect it from heat, 
frost, dryness, or too much moisture. Secondly, 
it has a supply of food which the seed uses when 
it begins to sprout. It takes quite a while for 
the baby plant to push through the earth to the 
light. As soon as it reaches the light and gets 
some green color in the stems and leaves, it can 
make its own food. Before then, it must use 
that which was stored in the seed. 

Every seed has two inside parts, the food 
supply, and the baby plant, which is called the 
embryo (pronounced em'bri-o). In many 
seeds the embryo is too small to be seen with¬ 
out a microscope, but in others it can be seen 
very clearly. If a peanut is split into its two 
halves the little embryo can clearly be seen up 
in one corner. Looking closely, a little stem 
and the beginning of leaves can be seen. The 
two halves are the storage places for food. 

There are two kinds of seeds: those whose 
storage rooms are split in two, like peanuts, 


STORAGE ROOMS 


75 


beans, and peas; and those which are all in one 
piece. The ones which split in two are the 
most interesting because you can see the embryo 



The storage room of some seeds is split in 
two, others are all in one piece 


so plainly. In the one-piece seeds, the baby 
plant is curled up in a mass of starchy matter 
and the whole is covered with the seed coat. 
The storage part of the seed is called a cotyledon 
(pronounced kot'i-li'don) and if it is all in one 
















76 


THE GARDEN OF THE WORLD 


piece it is a monocotyledon (mono meaning 
one). If it has two parts it is called a dicoty¬ 
ledon. Sometimes the names are shortened and 
they are called monocots and dicots. As the little 
plant begins to grow, it uses up the food. One 
of the first things it must do is break through 
the seed coat. Then it continues growing and 
growing. The more it grows, the more food 
it needs. By the time it gets to the sunlight, 
the food is all gone. Nothing is left but the 
empty seed coat, and it is torn and broken. 
However, that doesn’t matter, for the plant can 
take care of itself now it is in the sunlight. As 
fast as it grows, it works making food for itself 
from the air, water and soil. 

Seeds are of all sizes and shapes. Mustard 
seeds are famous because of their small size; 
many flower seeds are also very small. Nuts 
are good sized seeds. Often a single large seed 
or many small seeds are enclosed in a large juicy 
covering. Examples of this kind are to¬ 
matoes, apples, oranges, pears, plums, berries, 
and dozens more. Every seed, no matter how 


STORAGE ROOMS 


77 


it is born on the plant, has these three important 
parts, a seed coat, an embryo, and some stored 
food to give it a start in life. 

People eat a great many seeds because they 
can use the stored food also. We eat nuts, corn, 
wheat, beans, and peas, and many others. Of 
course we also eat the fruit that covers the seeds 
of apples and pears and similar fruits, but that 
is not quite the same as eating the seeds. An 
apple seed can still grow after the stored pulp 
around it is eaten away, but a peanut is finished. 
All plants provide many more seeds than could 
possibly grow so that we are not doing any 
damage when we eat the seeds. 

When people want to raise carrots or daisies, 
they plant seeds, but when onions or tulips are 
wanted, bulbs are set in the ground. A seed is 
very hard and dry. Before it can grow, the 
rain must soak through its hard coat and soften 
the baby plant inside. That baby plant or 
embryo is so tiny that it takes a good while for 
it to push through the earth to the light. When 
it does get through, it has to start making food 


What aye bulbs? 


78 


THE GARDEN OF THE WORLD 


in order to grow further. On the whole, it is a 
long performance. It takes quite a long time 
for carrots or daisies to grow to full size. 

A bulb, on the other hand, is juicy and fat. 
It is stuffed full of food and is all ready to grow. 
It doesn’t need much soaking. The tulip bulb 
has enough food for the use of the new plant. 
Consequently, as soon as warm weather comes, 
the tulip just shoots up. Before long there is a 
tulip blossom. Growing plants from bulbs is 
very much quicker than growing from seeds. 
But only a few plants have bulbs Most of 
these belong to the lily family. Tulips, daffo¬ 
dils, hyacinths, and all lilies have them. The 
onion belongs to this family too. Some flowers 
are especially fortunate to have bulbs. These 
are the early spring flowers that grow low on 
the ground in a deep forest. Because of their 
fast-growing bulbs they get an early start in 
the spring. By the time the leaves are on the 
trees, they are all through making and storing 
food for the next season. If they did not get 
through by this time, the forest would soon 

Bulbs are 
stuffed with 
plant food 



STORAGE ROOMS 


79 


become so shady that they could not get any 
light for their work. A familiar flower that 
uses its bulb to help it grow in this way is the 
dogtooth violet. 

A bulb is really an underground bud. It is 
made of thick overlapping scales. It can send 
up a shoot that becomes the new plant, and it 
can also produce new bulbs that grow out of 
the sides of the old one. Late in the summer 
these side bulbs can be pulled off and planted. 
The old one can also be used again. Some 
kinds of onions form bulbs above the ground. 
They have little bulblets in place of flowers. 
These are the “onion sets” that are bought for 
vegetable gardens. 

There is another reason why bulbs are planted 
instead of seeds. Tulips, for example, do not 
grow from seed in the United States because 
the climate is not right. They do nicely in 
Holland; therefore, the gardeners in Holland 
raise the plants and send the bulbs to this coun¬ 
try. Very often a plant will grow from a bulb 
in a climate where the seed will not do well at 


Tulips grow 
best from 
bulbs 




8o 


THE GARDEN OF THE WORLD 


Why are there 
laws against 
picking wild 
\flowers? 


all. This is because the bulb has so much food 
stored away that the plant can disregard climate. 
Bulbs do well in places where the summer is 
very dry, also. The plant grows so quickly 
that it is finished with its work when the dry 
season comes. If seeds had been used, the 
work would be just beginning and of course, 
would have to stop, because moisture is neces¬ 
sary for food-making. 

In nearly every wood or forest preserve, 
especially near large cities, there are signs which 
say, “Don’t pick the wild flowers.” People who 
do not think seriously are sometimes angered 
by these signs. They say the guardians of the 
forest do not want people to enjoy themselves. 
Many of them disobey the signs and pick the 
flowers anyway. Other people, who really 
think about the matter, realize that such a law 
adds to their pleasure because if visitors con¬ 
tinue to pick the flowers, they will soon dis¬ 
appear entirely. Many of our most beautiful 
spring flowers have vanished because of careless 
picking. The glorious white trillium which 


STORAGE ROOMS 


used to be very abundant, has become so rare 
that many people have never seen one. The 
trailing arbutus, one of the most exquisite and 
dainty of all spring flowers, has been torn up so 
carelessly that it now grows only in a few 
hidden spots. Flower lovers who know where 
it grows will not tell because they want to pre¬ 
serve it from the thoughtless crowds who would 
quickly pick it. 

Wild flowers are not like garden flowers 
which should be picked. Many of them pro¬ 
duce only one flower. The flower is at its 
prettiest before it has been pollinated. After 
pollination, it fades because its purpose in life 
has been completed. If it is picked before 
pollination, there will be no seeds this year. If 
it is an annual plant, one that dies down every 
season and has to start each spring from seeds, 
that is the end of its life. By picking one bunch 
of buttercups a thoughtless visitor may destroy 
a whole patch. 

A great many of our wild flowers, especially 
early spring ones, are perennials. That is, they 


82 


THE GARDEN OF THE WORLD 


have a bulb or a tuber or an underground stem 
that keeps alive all winter, sending up new 
shoots in the spring. Trillium, spring beau¬ 
ties, anemones, and violets are some of the 
prettiest flowers that are perennial. Such plants 
grow almost entirely in shady, moist places 
under the trees. The soil where they grow is 
so moist that it is impossible to pick a flower 
without pulling up the underground part as 
well. No matter how carefully people try, 
they are sure to injure that important part which 
means life to the plant. That is the reason 
why the delicate white trillium has disappeared. 
The red or purple trillium is not so attractive. 
People have left it alone, and it is still plentiful. 

Even though the valuable underground stem 
of the flower is uninjured, picking may do 
further damage. This bulb or stem, whichever 
it happens to be, can stay alive all winter, but it 
cannot do so unless it receives a fresh supply of 
food. The leaves are working busily making 
this food. The leaves of spring flowers, in par¬ 
ticular, must work very fast, because as soon as 


STORAGE ROOMS 


83 


the trees are covered with leaves they cut off 
the necessary sunlight. An early spring plant 
cannot spare one day of sunlight because its 
working season is so short, but if a careless visi¬ 
tor to the woods picks the flowers and the leaves 
with them, the work of making food is ended. 
The bulb will not have enough stored away to 
start the plant next year; therefore another 
spring flower has been destroyed. The place 
where spring beauties were growing this year 
will be bare or covered with weeds next spring. 

Communities have three good reasons for 
saying, “Don’t pick the wild flowers:” picking 
flowers destroys the chance for seeds; it is more 
than likely to kill the.roots of perennial flowers; 
it prevents the leaves from manufacturing 
enough food for the next year’s growth. 


Wild flowers 
should not 
be picked 







Chapter VI 


Will oranges grow 
on lemon trees? 


MAN-MADE PLANTS 

O RANGES sometimes grow on lemon 
trees, but it does not happen naturally. 
An orange grower often puts oranges on his 
lemon trees by grafting or budding. A man 
might buy some land to use for an orange grove 
and then find that the soil was not good for 
orange trees, but excellent for lemons. He does 
not become discouraged and sell his farm but 
instead lets some lemon trees get a good start. 
When he is sure the trees are strong and healthy, 
he goes to someone who has orange trees and 
gets some buds. He is careful to cut buds only 
from the very best trees. The bud is the grow¬ 
ing part of any plant. We usually think of 
buds as growing into flowers or leaves, but 
branches come from them also. This man will 
cut a bud from the orange tree in such a way 
84 


MAN-MADE PLANTS 


85 


that there will be a small oval shaped piece of 
barking clinging to it. Then he quickly cuts a 
T-shaped slit in the bark of the lemon tree and 



The bud from another tree will grow and bear 
its own bind of fruit 


slips the orange bud underneath. He covers 
the cuts with wax to keep the moisture from 
drying out and sometimes winds raffia or twine 
about the stem to hold the bud in place. 








86 


THE GARDEN OF THE WORLD 


If he has done a good job, the bud will begin 
to grow into a branch. That branch will bear 
oranges, not lemons . After the branch has had 
a good start and has produced enough leaves to 
make food for the tree, he may cut off all the 
lemon branches. Then he has an orange tree, 
but the roots are still those of the lemon tree. 
He can do this to his whole grove. It is not 
hard to do. The workman must be careful of 
just one thing. The growing part of a tree is 
just under the bark. He must make his cuts 
so that the growing part of the orange tree and 
the growing part of the lemon tree fit into each 
other exactly. If he cuts too deep or not deep 
enough, the bud will not be able to grow. 

Budding has made it possible to grow oranges 
in many places where they did not grow before. 
One kind of orange can be budded onto the 
roots of another kind. For example, Florida 
oranges are very sweet and juicy, but they will 
not grow except in very warm climates. A 
certain kind of Japanese orange will stand much 
colder weather, but its fruit is sour and bitter. 


MAN-MADE PLANTS 


8 7 


Someone thought of putting the Florida buds 
onto the Japanese trees, and now it is possible 
to raise Florida oranges much farther north 
than formerly. You can see that there is a 
great advantage in being able to do this. 

Often people who do not raise fruit to sell 
have fun making experiments with budding. 
A family may have room for just one tree in 
its yard. They probably will plant a lemon 
tree, for it is very hardy. Later they can bud 
onto that tree, oranges, grapefruit, and tanger¬ 
ines. Maybe they will have several different 
kinds of oranges. It is not at all unusual in 
California to see four kinds of fruit growing on 
one single tree. 

The different kinds of fruit must be closely 
related as oranges and lemons are. You cannot 
put apples on lemon trees, but you can grow 
apples on pear trees. There is a grove of prune 
trees in California now whose roots are the roots 
of almond trees. It is fairly easy to tell which 
trees will exchange this way by looking at the 
seeds. Orange and lemon seeds are alike, so 


88 


THE GARDEN OF THE WORLD 


How do farmers 
get better apples? 


are apple and pear, and prune pits are like 
almond pits. 

It is a curious fact that apple trees grown from 
seeds never have as good fruit as the apple which 
produced the seed. The seeds from a big juicy 
apple might be planted and develop into trees 
which bear small, sour fruit. Because this is 
true, farmers do not raise apple trees from seed 
but buy little trees from the nursery man. 
However, if a farmer wanted to take the time 
and trouble, he could get good trees by grafting, 
which is what the nursery man does. Grafting 
is very like budding, but is a little harder to do. 
It means attaching the twigs of one tree to a 
branch of another. 

This is what often happens: A farmer has one 
fine apple tree. The apples are big, juicy, 
mellow, and of a lovely red color. Around his 
orchard are several little seedlings from these 
same apples. They are strong and healthy, but 
he knows the apples they bear will not be so 
good as those of the parent tree. He cuts off 
one of these seedlings just above the ground 


MAN-MADE PLANTS 


89 


and makes a notch. Then he cuts, from his 
good tree, two twigs that have several buds, and 
he shapes their ends like a wedge. He fits these 



By means of grafting the fruit grower can improve 
the fruit the tree will bear 


into the notch, one on each side, taking great 
care that the growing parts of the stem and the 
twigs come together. Then he ties the twigs 
in place with raffia and covers the cuts with 



9 o 


THE GARDEN OF THE WORLD 


wax to keep out rain and bugs. If he has done 
his work carefully, the twigs will grow just as 
well as on their own tree, and in a few years he 
will have delicious fruit. 

The seedling to which the twigs are grafted 
is called the stoc\, and the twigs which are 
grafted on are called cions (pronounced si'ons). 
There are several ways of grafting—that is of 
cutting and fitting—but the principle is always 
the same. The growing part of the stock and 
the cion must fit together. The growing part 
of the tree is just under the bark. 

Sometimes grafting is used for another pur¬ 
pose. In France, the largest industry is making 
wine from grapes. Some years ago all the 
grape vines began to die. It was found that 
some plant disease had attacked the roots. For 
a time it seemed that all the vineyards would be 
lost. It was a very serious situation but at last 
somebody discovered that American grape vines 
could not catch this disease. They were im¬ 
mune to it. No matter how close they were 
placed to the diseased plants they grew and 


MAN-MADE PLANTS 


9 1 


thrived. The French began immediately to 
plant American grapes. However, these grapes 
are not sweet enough to make good wine. 
Therefore they grafted their French vines to 
the American roots. Now these grapes are 
just as they were before the disease attacked 
them. You could not tell the difference in the 
fruit, but the roots are strong and healthy. 
Grafting saved the French vineyards. 

The big, brilliantly white shasta daisy is not 
a natural flower, but one that was created from 
three less attractive daisies. Luther Burbank, 
a world-famous experimenter with plants, im¬ 
proved and changed many plants in a way that 
seems almost like magic by using a method 
called “crossing.” He had always been fond 
of daisies, but the American field daisy is not a 
very beautiful flower. It is strong and hardy 
and has a great many blossoms, but they are 
small and straggly. The stems are crooked and 
not very tall. In England there was a daisy 
much larger than ours with coarser stems and 
flowers. In Japan, there was a small daisy 


Burban\ 
created the 
Shasta Daisy 


How did Burban\ 
produce the 
shasta daisy? 







9 2 


THE GARDEN OF THE WORLD 


whose petals were so white they were almost 
dazzling. Mr. Burbank thought how wonder¬ 
ful it would be to have a daisy large and tall like 
the English one, strong and full of blossoms like 
the American, and a brilliant white like the 
Japanese. The shasta daisy has all these good 
qualities and this is how Mr. Burbank did it: 

He got the very best seeds he could find from 
the three different kinds of daisies and planted 
them. When they bloomed, he cross-pollin¬ 
ated them. That means that instead of allow¬ 
ing the pollen from one kind of flower, say the 
American, fall upon the pistils of the same kind, 
he took the pollen and with a small brush 
sprinkled it carefully on another kind, either the 
English or the Japanese. He saw to it that each 
flower received pollen from a different kind 
of daisy. He did not know which combination 
would be the best, so he tried a great many 
different ones. After the daisies had all been 
pollinated, he tied little bags over them to pro¬ 
tect them from any wandering bee with pollen 
on his legs that might come along and spoil the 


MAN-MADE PLANTS 


93 


experiment. When the seeds formed from 
these flowers, he saved and planted them. 
Later, when the flowers came from these seeds, 
he studied them carefully. Just as a little girl 
may have curly hair like her mother and blue 
eyes like her father, so some of these flowers 
were large and tall like the English daisy and 
a beautiful white like the Japanese. When¬ 
ever a flower had a good quality that he wanted 
to keep, he crossed the pollen from it with an¬ 
other good flower and saved the seed. When 
the plants grew from this seed, he saved only 
the best ones. Those that were tall, straight, 
white, large, strong, and many blossomed were 
chosen and he burned the rest. He selected the 
seed and planted it every year for eight years, 
destroying always those flowers that were not 
just right. All of this time was necessary be¬ 
cause plants inherit bad traits from their ances¬ 
tors just as people do. He wanted to be sure 
that none of the seeds would produce flowers 
that were small, straggly, or a dirty white color. 

At the end of eight years he was sure that the 


94 


THE GARDEN OF THE WORLD 


seeds would produce only beautiful flowers. 
Then he gave the seed to others, and soon there 
were shasta daisies growing in gardens all over 
the country. He named the flower for Mt. 
Shasta, a beautiful mountain peak in Cali¬ 
fornia, which is covered with shining white 
snow all through the year. 

Botanists call a flower like the shasta daisy a 
hybrid because it is produced by crossing the 
pollen of different kinds of plants, and it inherits 
the best points of each. Most hybrids are 
formed only by two kinds of plants. The shasta 
daisy is unusual because it comes from three. 





Chapter VII 


A WORLD OF GARDENS 

W ATER lilies are not so different from 
other plants as might be thought. Like 
all plants, they need air and sunlight, food and 
water. There are air chambers in the leaves 
floating on the top of the water. Therefore the 
plant can get plenty of air and sunlight. They 
live in the water so they never have any trouble 
in getting enough moisture, and they do not 
have to provide against drying out as land plants 
do. In Italy, where the summers are hot and 
dry, the leaves of ordinary plants must have 
an extra thick skin to keep the water from 
evaporating too fast. The water lily does not 
need any such help. The skin on its leaves is 
soft and tender. 

A water lily could not live in water alone. 
It has roots which go down to the soil under- 

95 


How do water 
lilies grow? 


9 6 


THE GARDEN OF THE WORLD 


neath the pond, for it must have nitrogen and 
other minerals which only the soil can supply. 
The biggest and best water lilies are found in 
ponds where the soil underneath is rich and 
black. If the pond has a sandy bottom, the 
lilies will not do so well there. 

Water plants have one advantage over land 
plants; they do not need strong woody stems 
to support them. They can save the energy 
other plants use in growing strong stems for 
building big leaves to make food and for beau¬ 
tiful flowers. They do not need long tubes in 
their stems and leaves to carry water because 
the water is near to all parts of the plant. 

Some water plants like bulrushes and cat-tails 
have strong stems. They are then able to grow 
on land as well as in the water. This is very 
useful to them in case their pond or stream 
should dry up. 

Some other water plants grow completely 
under water. They do not need strong stems, 
but they are at a disadvantage when making 
food, for the sunlight has to pass through the 


A WORLD OF GARDENS 


97 


water, which weakens it. The only air they get 
is that which has been absorbed by the water. 

On the whole, water plants do not get along 
as well as land plants. The nearness of water 
is a great help, but there are disadvantages. 

Many a prospector, looking for gold in the 
desert country of Arizona or California, would 
have died of thirst if it had not been for the 
cactus plant. All he had to do was chop off 
the top of the cactus with his ax, and he would 
find sweet water stored in its barrel-like stem. 
Of course, he took a chance of getting his hands 
full of thorns, but when one is dying of thirst, 
thorns are not very important. 

It seems queer that the cactus, which grows 
in places where there is no rain for months and 
months—sometimes for years—should be able 
to have so much water to store away. The 
reason is that it is especially built to hold water 
and keep it from evaporating. When there is 
a rain, it stores up enough water to last until 
the next rain, even though that may be months 
away in the future. 


4 


Why is 
full of 


a cactus 
water? 



























9 8 


THE GARDEN OF THE WORLD 


Leaves make food from water and carbon 
dioxide. The leaves also give of? water which 
evaporates into the air, a process called Tran¬ 
spiration . Trees drop their leaves in winter 
so they will not lose too much moisture. The 
cactus plant prevents the transpiration of water 
by not having any leaves. The stems have some 
green coloring, and they do the work of making 
food. Naturally they do not make it very fast, 
and for that reason the cactus grows slowly. 
The water is stored in the stem, which is very 
thick, sometimes over a foot across. All over 
the stem is a heavy skin which prevents evapo¬ 
ration. There are also hairs and thorns which 
keep the moisture inside. They serve to keep 
away prowling animals who might break the 
stem and so let some of the precious water 
escape. The skin, in addition to being thick, 
is rather waxy. Wax prevents evaporation. 
That is why we wrap food in wax paper to keep 
it fresh. The only way water can get out of 
this armored plant is when some outside agent 
like the prospector with his ax, breaks through. 


A WORLD OF GARDENS 


99 


The cactus has many forms. Although 
some may grow to a height of fifty feet and have 
many branches, like the giant cactus, most of 
them are much smaller. A common kind is 
the barrel cactus which is something less than a 
foot across and from a foot to six feet tall. It 
has deep furrows and many sharp thorns. An¬ 
other common variety is the prickly pear, which 
has flat, jointed stems shaped something like 
the sole of a big shoe. It has prickles instead 
of thorns. Because of their ability to store large 
amounts of water, the members of the cactus 
family are found in dry regions where very 
few other plants can grow. Such places are 
Mexico, Arizona, New Mexico, and Southern 
California where the climate is dry. 

The Arabs, who know all about dates because 
they depend upon them for food, have an old 
saying that the date palm must have its feet in 
the water and its head in the furnace. As a 
matter of fact, date palms only grow in the oases 
or parts of the desert where there is some water. 
Nothing can grow where there is no moisture 


Cacti are found 
in dry places 









100 


THE GARDEN OF THE WORLD 


Why do dates 
grow in the 
desert? 


at all. The old Arab saying means that the date 
palm must get all the moisture that it needs 
through its roots. If its leaves or stems are wet 
by rain, it does not do so well, and may even 
die. In a desert, such as the great Sahara, this 
condition is possible. The water is brought to 
an oasis by underground streams, not by rain. 
It so seldom rains in this desert that we can 
almost say never. While the date tree’s roots 
are absorbing this underground water, the great 
feathery crown of the tree is hot and dry under 
the sun. The hotter the sun the better the tree 
thrives and the bigger it grows. 

A single oasis may have many thousands of 
date trees growing there. There are some oases 
which have as many as half a million trees. A 
single bunch of dates from one of these trees 
may weigh from one hundred to five hundred 
pounds. Each of these date palms bears an 
enormous bunch of fruit every year, so it is not 
surprising that dates are the chief food of the 
desert dweller. He can live many days, and 
often has done so, on dates alone. 


A WORLD OF GARDENS 


IOI 


Farmers have tried to raise dates in many 
places in the United States but have not been 
very successful. We have very few places 
where there is underground water, no rainfall, 
and plenty of hot sunshine. The best place 
seems to be in Arizona, near Phoenix, and many 
trees have been planted there, and have been 
growing for a number of years. It is too soon, 
however, to tell whether they will be perfectly 
successful, for a date palm should live for at 
least a hundred years. When the year 2000 
comes, we should know if Arizona is a good 
place for the growing of dates. 

Usually we think of a desert as being hot, but 
the word really means a dry country. The cold 
arctic regions are deserts because they are frozen 
for two-thirds of the year. Plants cannot use 
frozen moisture. In the arctic countries there 
is a short season in the summer when the ice 
melts and the snow thaws out. A plant that 
can manage to grow so quickly that it is through 
flowering before the frost comes again may live 
in these cold deserts. 



Some oases 
have thousands 
of date palms 







102 


THE GARDEN OF THE WORLD 


What plants grow 
in the cold 
deserts? 



There are only a few plants that are able to 
work so fast. The only common plant in the 
frozen north is the reindeer moss. There are 
also some little flowering plants that have small 
bright flowers. Some of them even have 
berries. Trees grow there, too, but would not 
be recognized as trees. The summer is so short 
that the tree can grow only a tiny bit each year. 
A larch tree that is fifteen years old may be 
only a few inches high. 

In the extremely cold deserts of the antarctic 
there are practically no plants at all. 

High mountains are sometimes cold deserts 
also. Traveling from the base of a high moun¬ 
tain to the peak is something like traveling from 
the equator to the north pole. At the base are 
the luxurious plants of the warm climate. 
Farther up the weather becomes colder and the 
season of winter lasts longer. First the hard 
wood trees give up, and only the conifers are 
left. Conifers or cone-bearing trees, like the 
pines and firs, can grow in quite severely cold 
climates. At length, however, the climate be- 



Alpine plants 
must grow 
quic\ly 




A WORLD OF GARDENS 


103 

comes too severe for them. The highest place 
where trees can grow is called “timber line.” 
Above this point there are no trees. From here 
to the peak of the mountain the plants become 
smaller and smaller and more like the plants of 
the arctic regions. If the mountain is very high 
and the peak covered with snow all the year 
around, there will be no plants at all, as in the 
antarctic where there is always snow. 

The grasses are the most important family 
in the plant kingdom. They cover the earth. 
There are over one thousand different kinds of 
grasses and they grow in every climate where 
anything can grow at all. The largest grasses 
are the bamboos, which grow in hot countries; 
and the smallest are tiny plants no taller than 
moss which grows in very cold climates like Ice¬ 
land and Siberia. The world would be a much 
poorer place if it were not for grass. Indeed, it 
would be impossible for men to live at all. 

In the first place, the roots of grass form a 
network which binds the soil together. If they 
did not, the wind would be constantly blowing 


What is the most 
important family 
in the plant 
\ingdom? 


THE GARDEN OF THE WORLD 


104 



the sand and earth from one place to another. 
Larger plants, like trees, could not grow because 
the soil would not stay in one place long enough. 
Grass roots hold the soil in one place. They 
also keep rain from washing it away. 

In the second place, grasses are the most im¬ 
portant food materials in the whole world. 
Farm animals—horses, cows, sheep—live on 
grass. Dried grass, in the form of hay, supplies 
them with food all winter. Grasses supply man 
with most of his food. Corn, wheat, rye, bar¬ 
ley, rice, and oats are all grasses. All of these 
plants, except corn, have been grown to feed 
men since long before history was written. In 
Bible times the raising of wheat was an old pro¬ 
fession. In China and India the people live 
almost entirely on rice and have done so for 
thousands of years. White men did not have 
corn till America was discovered, but the 
Indians had probably eaten it for hundreds of 
years before that time. 

Sugar cane is another grass. How we should 
miss its sweetness if it should suddenly vanish 
from the earth. 


Corn is one 
of the grasses 




A WORLD OF GARDENS 105 

In some hot countries bamboos supply food, 
clothing, and shelter. In some islands in the 
South Seas, boys and girls wear jackets of bam¬ 
boo, live in bamboo houses, and gather tender 
young bamboo shoots to eat for vegetables. 
They use sections of the smaller bamboo stems 
for cups and the larger ones for pails. The 
fiber is also used in making paper and rope. 

Not the least of the grasses’ service to man¬ 
kind is in supplying beauty. How ugly the 
fields and yards would be if they were not 
covered with a soft green carpet of grass. 

A weed is any plant out of place. A rose 
bush might be called a weed if it grew in a field 
of wheat, and so might a corn stalk if it grew in 
a flower garden. Usually, however, the word 
weed means a plant that is not wanted any¬ 
where. The ragweed, cockle-bur, dandelion, 
thistle, and plantain are always a nuisance and 
are not welcome in any place. Weeds spoil the 
appearance of lawns and gardens. They take 
up light and space that other plants need. They 
steal moisture and nourishment from the soil, 


Bamboo is the 
tallest grass 










THE GARDEN OF THE WORLD 


What are the most 

troublesome 

plants? 


106 

preventing the garden flowers or grass from 
growing well. If they grow in the grain fields, 
their seeds are mixed with the grain at harvest 
time and lower the price the farmer can get for 
his crop. The weeds are not good for cattle 
and spoil the milk if a cow has eaten them. 
The pollen from ragweed gives hay fever to 
many people. 

That is what people think about weeds. 
From the plant point of view, a weed is among 
the most successful of plants. It can do all of 
the things that a plant most needs to do. It 
grows in almost any soil or in nearly any 
climate. It crowds out any plants that are in 
its way and it produces an enormous number of 
seeds. That last fact is the most important. 
Consider how many seeds are sure to be lost 
every year. The plant which has the most to 
begin with is the one which will produce the 
most new plants the next season. 

The best way to prevent weeds from growing 
in our fields and gardens is to keep them from 
going to seed. Most of them are the kind of 


A WORLD OF GARDENS 


107 

plants that are known as annuals. That means 
they live only one season and must start anew 
from seeds the next year. If this year’s plants 
are kept from forming seeds there will not be 
any plants next year. If everyone would be 
careful to cut away every weed he saw before 
the blossoms had turned to seed, we could be 
entirely rid of many kinds of weeds. That 
would mean quite a great deal of work, but it 
would surely be worth it. 

There are some weeds which could continue 
growing even though they did not produce any 
seeds. These belong to the kind of plants 
known as perennials. That means that the 
undergound part of the plant stays alive from 
year to year in spite of the fact that the top 
dies. Each spring this underground stem 
sends up new green shoots. If we could keep 
these shoots from growing, the plant would die 
finally, because the green leaves above the 
ground would be unable to manufacture food 
and so the undergound stem would die. When¬ 
ever you see a weed starting to grow, cut it off 


Why do forests 
need protection? 


108 


THE GARDEN OF THE WORLD 


down to the ground. Cut it every time it 
starts, and at last it will be too weak to try again 
because it will have used up all its stored-up 
food without being able to make any new. 

We could do a great deal toward freeing the 
country of troublesome weeds if everyone would 
do these two things: cut all weeds before they 
go to seed, and cut all young shoots before they 
can make food. 

When the first settlers came to America, they 
found the new country covered with forests and 
prairies. For hundreds of years no one had 
disturbed the plants which grew here and they 
had been progressing in the natural way. In 
the natural way the prairies come first. Grasses 
and flowering herbs like daisies grow in the 
prairies. After many years the soil becomes 
much richer, because the leaves from these 
plants have dropped every year and decayed. 
The decayed leaf mold, or humus, as it is called, 
makes a rich soil that is suited to trees. Also it 
holds water better than the light soil of the 
original prairie. Gradually trees begin to grow 


A WORLD OF GARDENS 


109 

and in time the prairie disappears to be replaced 
by a forest. 

When trees and prairies are allowed to grow 
by themselves, they still follow this succession. 
The thousands of new settlers coming to Amer¬ 
ica, however, changed all this. First of all, 
they needed homes and fire; so they chopped 
down trees to build log cabins. Later they 
built board houses. They burned wood to heat 
their homes and to cook their food. The next 
thing they needed was food; so they plowed 
up the prairies for farms. Often times a forest 
would interfere with a man’s farm, and he 
would kill the trees to get them out of the way. 

At first no one realized what a serious mis¬ 
take these people were making. Only about 
fifty years ago, the citizens began to wake up. 
They discovered that their fine forests were dis¬ 
appearing. The forests in the eastern United 
States are about gone. Wood has become very 
expensive, although we need it more than ever. 
Trees cannot be replaced in a year like corn or 
wheat. It takes fifty to a hundred years, at 


110 


THE GARDEN OF THE WORLD 


least, to produce a tree large enough for lumber. 

After our trees were gone, we discovered an¬ 
other service that forests do for man. They 
prevent floods. The roots of trees hold the 
moisture and let it go very slowly. When the 
trees are gone, the fast melting snow or heavy 
spring rains carry the soil away because there is 
nothing to hold it. Many hillsides have been 
washed bare of soil when the trees were either 
cut down or uprooted. 

The United States government is trying very 
hard to save the forests which are left and to 
plant new forests to replace the old ones. The 
government hires forest rangers to watch for 
forest fires, as many hundreds of trees are lost 
by fire each year. The government also tries 
to persuade lumber companies to plant a new 
tree every time an old one is cut down. 

All trees are beautiful, and most of them are 
useful. They grow usually in family groups. 
The northern forests are made up of conifers or 
soft wood trees. They are called conifers be¬ 
cause they have cones which hold the seeds. 


A WORLD OF GARDENS 


hi 


Most of the conifers are evergreen and have 
needle-like leaves. Pines, cedars, firs, and 
spruces are well-known examples of the coni¬ 
fers. They can stand long cold winters and 
dry summers. Besides growing in the northern 
forest, they are also found in the south along 
the mountain ranges which have a colder 
climate than the lowlands. 

The hardwood trees, which drop their leaves 
in the autumn, require a rainy spring, a warm 
summer, and rich soil. They grow in the 
central parts of our country where these condi¬ 
tions can be found. The oak, beech, and maple 
trees form most of our hardwood forests. 

And so, it is no wonder that our world is full 
of gardens, that it is a world of plants, growing 
not only on the land, but in water, in the hot 
and cold deserts, and even on the mountains. 
Wherever there is sunlight and moisture, there 
we find plants at work, running their factories 
so that the world will never be without its 
gardens. 


f 



% 


* 


9 



















































